package com.hmdp.utils;

import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Component;

import java.time.LocalDateTime;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;

@Component
public class RedisIdWorker {
    private static final Long BEGIN_TIMESTAMP = 1640995200L;
    private final StringRedisTemplate stringRedisTemplate;
    private final int COUNT_BITS = 32;

    public RedisIdWorker(StringRedisTemplate stringRedisTemplate) {
        this.stringRedisTemplate = stringRedisTemplate;
    }

    public Long nextId(String keyPrefix){
        Long now = LocalDateTime.now().toEpochSecond(ZoneOffset.UTC);
        Long timestamp = now-BEGIN_TIMESTAMP;
        String date = LocalDateTime.now().format(DateTimeFormatter.ofPattern("yyyy:MM:dd"));
        Long decrement = stringRedisTemplate.opsForValue().decrement("icr:" + keyPrefix + ":" + date);
        return timestamp<<COUNT_BITS | decrement;
    }
}
